LOS ANGELES (AP) _ The three surviving Frustaci septuplets, now 2 years old, have made progress in the past year but are still lagging in their development, a lawyer for their parents said.

''The past year has been marked by some improvement and progress, but Steven, Richard and Patricia Ann still receive medical attention and examination as well as developmental therapy,'' attorney Browne Greene said Thursday, the children's second birthday.

Seven children were born to Samuel and Patricia Frustaci on May 21, 1985. One was stillborn and three others died within 19 days. The couple, who have a malpractice suit pending against the doctor who prescribed a fertility drug, have generally avoided publicity since then.

Greene said the children no longer require oxygen or heart monitors, but their neurological and other problems continue to worry the family. Hearing impairment is suspected as a cause of their lag in learning to talk, and further testing is planned.

''For the family, the tremendous uncertainty of their future is the most difficult to bear,'' he said. ''Sam and Patti are trying to cope with each day as it comes and to do the best they can.''

Steven is not yet walking or talking, Greene said, and his cognitive level has been tested at 12 to 15 months. His feeding tube was removed just last month, and he still has difficulty eating.

Richard also shows cognitive delays. He has been walking for about a month and is still not talking, Greene said. Patricia Ann has been walking for several months and has a two-word vocabulary.

The Frustacis also have a healthy son, 3-year-old Joseph.

Mrs. Frustaci had taken Pergonal, an infertility drug. The couple filed a $3 million lawsuit against Dr. Jaroslav Marik of Los Angeles, after the four babies died.

The Frustacis claim Marik failed to perform tests that would have shown that Mrs. Frustaci was likely to conceive seven children. The suit alleges wrongful death, physical pain and mental anguish.

Marik has denied wrongdoing and declined comment on the suit.